This invention relates to gun ammunition projectiles and particularly to frangible projectiles and more particularly to frangible projectiles for use in pistol or rifle ammunition of 50 caliber or smaller.
In the art there exists a major concern relating to the danger associated with ricocheting projectiles fired from guns, especially from pistols and rifles of 50 caliber or smaller calibers. Major litigation has arisen seeking monetary recovery from law enforcement officers and/or governmental agencies as compensation from injury to a bystander or other innocent person struck by a ricocheting projectile or portion of a projectile. Also importantly, ricocheting projectiles are a very present danger to fellow law enforcement officers when gunfire erupts within a closed area, such as border patrol officers inspecting the holds of ships for contraband, etc. Further, training of law enforcement officers commonly includes participating in exercises which include entry into a “live fire house”. These exercises involve rapid entry by a number of officers into a “live fire house” training building and live firing of weapons at designated targets within the building. The presence of several officers within the enclosure, each of which may be firing their weapon, generates a real danger of injury of an officer by reason of their being struck by a ricocheting portion or all of a projectile.
Projectiles of the prior art have almost exclusively included a lead core, either with or without an outer covering of the core. In either event, lead has been recognized as an environmental pollutant and is now either banned or being considered for banning, in gun ammunition projectiles. Moreover, lead projectiles tend to ricochet from many surfaces which have a hardness on the order of a hardwood or even from the ground.
Accuracy of delivery of a projectile to an intended target is of importance in any shooting situation, but is of great importance in competitive sport shooting and in certain military and/or law enforcement shooting situations. Of especial concern is the repeatability from projectile to projectile of accuracy of delivery of the projectiles to a target.
To solve both the environmental concerns and the ricochet tendency of lead projectiles, there have been developed projectiles formed from a combination of materials which are collectively frangible when the projectile strikes a solid or semi-solid target. In those instances where these newer projectiles include a core which is housed within a jacket, such as copper, brass or other metal or metal alloy, the frangibility of the jacket is of concern. For example, fragments of the jacket may ricochet off an intended or unintended target and become independent small projectiles which can be injurious to an unintended target, such as a bystander or even the shooter. Depending upon various factors such as distance, outerwear protection, size of fragment, etc., such fragments can be lethal.
The present inventor has found that dislodgement and escape of powder particulates from the trailing end of a powder-based core exposed to the heat and blast forces generated by the burning powder within the case of a round of ammunition create at least two deleterious effects.
First, the center of gravity of the projectile is altered by the loss of the dislodged powder particles. The quantity of particles dislodged is different from projectile to projectile so that there is no consistency in the degree of alteration of the center of gravity between projectiles. This unpredictable alteration of the center of gravity of the projectile causes the projectile to exhibit more or less tendency to “yaw” along its free flight path to a target, with resultant inaccuracy of delivery of the projectile to the target. This problem, in its more severe state, can actually lead to the projectile assuming a tumbling action during its free flight to a target.
Second, in those instances where the powder-based core of the projectile is incorporated into a metal jacket and the initially open end of the jacket becomes the trailing end of the projectile, upon the projectile being fired down the barrel of the weapon, the trailing end of the core is exposed to the blast of the burning gun powder held within the case in which the projectile is disposed. Unless this initially open trailing end of the jacket is closed by some means, it has been found that individual particulates of the powder-based core break away from the core and exit the unclosed open end of the jacket. Such particulates, especially when they comprise a heavy metal, such as tungsten, etc., have further been found to affect damage to the bore of the barrel of the weapon, and in some instances, affect physical injury to personnel who may be disposed adjacent the muzzle of the weapon at the time it is fired. The hazardous nature of such loose powder particulates (which may comprise a grouping of multiple individual powder particulates bound together into a larger missile) has prompted the establishment of a test for powder-based projectiles which provides a type of measure of the quantity and/or size of loose powder particulates exiting the muzzle of the weapon and striking a sheet of paper positioned substantially perpendicular to the flight path of the projectile and at a distance of about ten feet from the muzzle of the weapon. This test provides information as to the density of loose powder particles exiting the weapon, the size of individual ones or groups of particles, and their spatial relationship to the actual flight path of the projectile.
It has been proposed that prevention of the release of powder particulates from the trailing end of a jacketed powder-based projectile may be affected by incorporating within the jacket a solid metal closure disc that is placed within the jacket in overlying relationship to the trailing end of the powder-based core, and thereafter the rim of the open end of the metal jacket is folded radially inwardly of the jacket to engage and anchor the solid metal disc within the jacket. Whereas this proposed procedure can be effective to block the egress of loose powder particulates from the trailing end of the projectile, it presents a more serious problem in that the solid metal disc does not readily disintegrate when the projectile strikes a solid or semi-solid target. Rather, the solid metal disc becomes a potentially lethal missile in and of itself and therefore presents a hazard which can be more serious than the hazard associated with individual powder projectiles.